Acetylenic tetrahydroisoquinoline derivatives



Unitgd grates Patent TETRAHYDROISOQUINOLINE DERIVATIVES .lohn H. Biel, Milwaukee, Wis, assi'gnor to Lakeside Laboratories, Inc., a corporation of Wisconsin No Drawing. Application May 28, 1956 v Serial No. 587,488

15 Claims. (CL 260-72415) .ACETYLENIC This invention relates to the production of novel chemical compounds. More particularly, this invention is concerned with novel alkyne. derivatives of 1,2,3,'4-tetrahydroisoquinolineand processes of preparing such compounds.

According to the present invention there are provided compounds of the formula N-(CHi).--CEC,(OHi)-'N wherein n and m are integers from 1 through 10, and

is a secondary amino groupsuch as a dialkylamino group, particularly such groups in which the alkyl moieties are lower alkyls, groups in which the nitrogen is part of a heterocyclicstructure, i. e.,,R and R are joined to each other and formv a ring, such as N-pyrrolidino, N- piperidino and N-morpholino, lower alkenyl groups,

aralkyl groups and aryl groups, particularly monocyclic aralkyl and aryl groups, and acid addition and quaternary ammonium salts thereof. j Also provided are processes of producing these compounds and intermediate compounds useful in such processes.

Production of such compounds is effected by reacting on appropriate dihaloalkyne of the formula 4 7 Y-(CHD-t-CEC-(CHah-Y with an amine of the formula I N-R toproduce the desired compounds of the formula 3,1 l *(C 2)n C-EO-'(CHz)mN I \R4Y n Y R1 wherein R R, m and n have the significance assigned above, Y is bromine, chlorine or iodine, and R andR are hydrogen or lower alkyls.

- tetrahydroisoquinoline.

ICC

Representative of the dihaloalkyues which may be used in the first step of this process are 1,4-dibromo 2- butyne, 1,5-dichloro-2-pefityne, 1,6-dichloro-3-hexyne,

1,7 dichloro13-heptyne, 1,8 diiodo-4-octyne, 1,12-dibromo-G-dodecyne, .1,15-dibromo-7-pentadecyne, and the like.

As indicated by the formula above, both secondary and'tertiary aminesmay be used in the process, including the amines trimethylamine, triethylamine,ptributylamine, dimethylamine, diethylamine, dipropylamine, diallylamine, methylethylamine, dibenzylamine, diphenylamine, pyrrolidine, morpholine, tpiperidine, methylaniline, and dibenzylmethylamine.

The dihaloalkyne and secondary or tertiary amine are conveniently contacted in the presence of an inert organic solvent for effecting the reaction. Examples of suitable solventsthat may be used'are toluene, benzene, acetonitrile, chloroform, pentane and lower alcohols. erally, the reaction proceeds at room temperature although elevated temperatures such as the reflux temperature may be employed to promote the reaction. The

reaction is usually terminated in about 1 to 12 hours or at such earliest time as it is essentially complete; The desired product may be recovered from the reaction rm'xture by conventional methods. Thus, if the product precipitates from the reaction mixture it may be filtered and purified by recrystallization from a suitable organic solvent. Products formed which are soluble in the reaction medium may be recovered by evaporation of the solvent.

The amino-halo-alkynes so produced may be recovered directly in the form of acid addition salts or quaternary ammonium salts depending on the amine reactant employed. The use of secondary amines gives a hydrohalic acid by-product which immediately forms an acid addi tion salt with the product. Tertiary amines having an alkyl group form alkyl esters of the halogen acids as byproducts (he, methyl chloride) which combine with the product to form the corresponding quaternary ammonium salt. By contacting the acid addition salts with an inorganic basic material the corresponding free base may be obtained.

Typical of the compounds'produced according to this first step are ,1-dimethylamino-4-bromo-2-butyne, lbromo-4-pyrrolidino-2-butyne, 1 chloro 5 morpholino- Z-pentyne, 1-chloro-6-piperidino-3-hexyne, 1-chloro-7-, di-

allylamino 3 heptyne, l iodo -,8 diethylamino-4- octyne, 1 bromo-12-dibutylamino-6-dodecyne and lbromo-15-morpholino-7-pentadecyne and hydrohalic acid addition and alkylhalo quaternary ammonium salts thereof.

As previously shown, the amino-halo-alkyne-intermediates, or salts thereof, may be subsequently reacted with l,2,3,4-tetrahydroisoquinolineor an N-alkyl-1,2,3,4- tetrahydroisoquinoline to form the desired aminoalkynyl- The N-alkyl 1,2,3,4 tetrahydroisoquinolines which may be used in thisprocess are those in which the N-alkyl groups are lower alkyls such as methyl, ethyl, propyl,"butyl, octyl, and thelike.

Reaction between the amino-halo-alkyne and tetra-. hydroisoquinoline may be conveniently etfected under liquid reaction conditions as byuse of an inert organic.

solvent. Such solvents as those named above may also be employed for this reaction. To promote the reaction,

it is preferred to employ elevated temperatures, such as the reflux temperature. Although an excess of either-re; actant may be used, it is generally advisable to employ stoichio'metric ratios. Upon termination of thereaction, the desired product is recovered by conventional pro;

cedures.

This reaction leads directly to 'the'fformation;oiacigid addition and quaternary ammonium salts of the desired Patented .Apr. 8, 1958 Gen- 7 hour products which may be recovered as the salt or the free base. Treatment of the salts with an appropriate amount of an inorganic'basic substance converts the salts to the free base. a v V Representative of the tetrahydroisoquinoline derivatives'which maybe formed bythis process are N-(4-dimethylar'nino 2 butynyl) -1,2;3,4 tetrahydroisoquinoline, N (4 dietliylamino 7 2 butynyl) 'l,2,3,4 -'tetrahydroisoquinoline, N [(4 (N pyrrolidino) 2-. butynyl)] 1,2,3,4 tetrahydroisoquinoline, N (4 N piperidino 2 butynylj 1 2,3,'4 tetrahydroisoquinoline, N [4 (N morpholino) 2 butynyl] 1,23,4- tetrahydroisoquinoline and similar compounds in which the butyne group is replaced by other alkynes such as Z-pentyne, 3-he ryn e, 3-he'ptyne; 4-octyne, 6-dodecyne', 7- pentadecyne and the like. i

The free base of such compounds may be converted to acid addition and quaternary ammonium salts by reacting the free base with up to two molesofanfacid' oralkyl esterof'an acid.

Mineral acids such as sulfuric acid or hydrochloricacid, or organic acids such as formic acid and citric acid,'n iay be used toformsalts. i j w Quaternary "ammonium salts are readily produced by contacting the alkyne 'with analkyl ester of mineral and organic acids such'as methyl chloride; ethylbromid'e; methyl sulfate and so forth.

' These 'novel tetrah' droisoqu inoline derivatives and salts thereof are potent hypotensiv'e agents" smother fore, are useful in alleviating hypertension. Thyfmay beformula'ted in the conventional pharmaceutical forms for; this purpose,' such as tablets, capsules, solutions and th'elike.

The following examples are presented to show methods of producing certain of the novelcompp'unds included within this invention. It is understood; liowe'v'ei'f'that these examples are included onlyfor purposes of illustration',"and that the invention is not to'be restricted to the embodiments specifically disclosed therein."

EXAMPLEI 4 bdimethylamirta-d-bromo-Z-butyize-methobromide BrTcm wHm Hm-cmm I 7 EXAMPLE 3 N-(4-dimethylamino-Z-butynyl) -I,2,3,4-tetrahydr0- isoquinoline dimethobromide To 0.125 mole of the oily l-bromo-4-diethylamino-2- butyne methobromide prepared as in Example 1 and dis,- solved in cc. of acetoni trile was added 10.3 g. (0.070 mole) of N-methyl-1,2,3,4-tetrahydroisoquinoline. The mixture was allowed to stiruntil a crystalline. precipitate appeared, which was isolated by filtration and recrystallized from 450 cc. of isopropyl alcohol. Yield 13 g.; M. P. 200-201 C. dec.

Analysis.-Calcd. for CmHgoBl'gNgiBl', N, 6.27. Found: Br, 35.63; N, 6.28. p s

, EXAMBLB 1 -br0mo-4-pyrrolidin0-2-butyng methqbrqmide This compound was prepared from 1,4-dibromo 2- butyne and N-methyl-pyrrolidine benzene as. described in Example 1. The oily productwas the sequentreaction.

EXAMPLE 5 N-[ (4-(Npyrrolidino)-2-butynyl) ],-1,2,3,4-tctra hydrbiso'quiholi'ne dimeth obrom ide 7 EXA L -bromo-4-N -piperidino-Z-butygryl mqthqlgriqmidq To 26.5 g. 0.125 mal or ifir dibrorno-g butyne in, 60 cc. of anhydrous ben z ene'we're'adcl'ed'8l5 g. (0.085 mole) 'of N-methylpiperidine in 20 cc. of benzene. An oily product precipitated. Theibenzene layer was decanted and the oil dissolved in 50 cc. of acetonitrile. An insoluble precipitate. removed by filtration. The acetonitrile filtrate was used in the subsequent reaction.

7 ridim-Z-butynyl -1 ,2,3,4-tetrahydroiso- NqG H2C;CC H71 23:-

CH: 7 CH: v To the a e ea el s st saai l-bsaaat-litnsridinsr Z-butynyl methobromide (Example 6) 'was' added 13.2 g. (0.09 mole) of N-methyl-1,2,3,4-tetrahydroisoguinoliue in cc. of acetonitrile. The oil which precipitated soon crystallized on further stirring-29 g. of apink solid were isolate'dbyfiltration and recrystallize'dfrom 240 cc.

EXAMPLE 8 CH3 CH3 To 8.0 g. (0.026 mole) of l-bromo-4-N-morpholino- 2-butynyl methobromide-prepared as per Example 1 suspended in 80 cc. of ethanol was added 4.0 g. (0.028 mole) of N-methyl-1,2,3,4-tetrahydroisoquinoline in 50 cc. of ethanol. The resulting mixture was refluxed with stirring for one hour and the solution clarified by filtration. The filtrate yielded a crystalline precipitate on standing. Yield 3.0 g., M. P. 219-220 C.

Analysis.-Calcd. for C H Br N O: Br, 34.80; N, 6.08. Found: Br, 32.80; N, 6.02.

Various changes and modifications of the invention can be made and, to the extent that such variations incorporate the spirit of this invention, they are intended to be included within the scope of the appended claims.

What is claimed is:

1. A compound of the formula R2 wherein m and n are integers from 1 through 5, and R and R are members of the group consisting of lower alkyl groups, phenyl-lower alkyl groups, phenyl groups, lower alkenyl groups and heterocyclic groups formed by joining R' and R of the group consisting of pyrrolidino, piperidino and morpholino groups, and nontoxic acid addition and quaternary ammonium salts thereof.

2. N-(4-di-loweralkylamino-2-alkynyl)- 1,2,3,4-tetrahydroisoquinoline in which the alkynyl group is more than 3 carbons and less than 11 carbons.

3. N-(4-di-loweralkylamino-Z-alkynyl)- 1,2,3,4-tetrahydroisoquinoline di-loweralkylhalide salt in which the alkynyl group is more than 3 carbons and less than 11 carbons.

4. N- (4-N-pyrrolidino) 2-alkynyl] -1,2,3,4-tetrahydroisoquinoline in which the alkynyl group is more than 3 carbons and less than 11 carbons.

5. N-[(4-N-pyrrolidino)-2-alkynyll-1,2,3,4-tetrahydroisoquinoline di-loweralkylhalide salt in which the alkynyl group is more than 3 carbons and less than 11 carbons.

6. N-(4-N'-piperidino-2-alkynyl)-l,2,3,4-tetrahydroisoquinoline in which the alkynyl group is more than 3 carbons and less than 11 carbons.

7. N-(4-N'-piperidino-2-alkynyl)-1,2,3,4-tetrahydroisoquinoline di-loweralkylhalide salt in which the alkynyl group is more than 3 carbons and less than 11 carbons. 8. N- [4-(N-morph0lino) -2-alkynyl]-1,2,3,4-tetrahydroisoquinoline in which the alkynyl group is more than 3 carbons and less than 11 carbons.

9. N- [4- (N-morpholino -2-alkynyl] -1,2,3,4-tetrahydroisoquinoline di-loweralkylhalide salt in which the alkynyl group is more than 3 carbons and less than 11 carbons.

10. N-(4-dimethylamino-2-butynyl)- 1,2,3,4-tetrahydroisoquinoline.

l1. N-(4-diethylarnino-2-butynyl)- 1,2,3,4 tetrahydroisoquinoline.

12. N-[4-N-pyrrolidino)-2-butynyl)J 1,2,3,4 tetrahydroisoquinoline.

13. N-(4-N-piper idino-2-butynyl) 1,2,3,4 tetrahydroisoquinoline.

14. N-[4-(N-morpholino)- 2-butynyl]-1,2,3,4 tetrahydroisoquinoline.

15. The process which comprises reacting a compound of the formula with a compound of the formula l as to produce a compound of the formula I N (CHs)nCEC*-(CH2)nN Ru; R Y R wherein Y is a member of the group consisting of chlorine, bromine and iodine, m and n are integers from 1 through 5, and R and R are members of the group consisting of lower alkyl groups, phenyl-lower alkyl groups, phenyl groups, lower alkenyl groups and heterocyclic groups formed by joining R and R of the group consisting of pyrrolidino, piperidino and morpholino groups, and R and R are members of the group consisting of hydrogen and lower alkyl groups.

References Cited in the file of this patent FOREIGN PATENTS 896,810 Germany Nov. 16, 1953 U S DEPARTMENT OF COMMERCE PATENT OFFICE CERTIFICATE OF CORRECTION Patent NO. 2, 830,049 John H Bie'l April 8, 1958 It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4, line 2, for N-(4-diniethylamino-2- read a:- N-(4-di'ethylaminoe Signed and sealed this 1st day of July 1958,

(SEAL) Attest:

KARL H. AXLINE ROBERT C. WATSON Attesting Officer Comnissioner of Patents 

1. A COMPOUND OF THE FORMULA
 14. N-(4-(N-MORPHOLINO)-2-BUTYNYL)-1,2,3,4,-TETRAHYDROISOQUINOLINE. 